1. Field of the Invention
The present invention relates to the maintenance of cross-country pipelines, and more particularly to a device for coating the internal surface of a pipeline with a cement-sand mixture.
2. Description of the Prior Art
Repair work at pipeline transport is becoming increasingly important in the world today. During repair or the construction of new pipelines a protective coating of a cement-sand mixture is applied on the internal surface thereof. This coating is very durable.
Most diversified equipment is used to form a coating from the cement-sand mixture (cf. e.g., Instructions on the Maintenance of the Equipment for Applying a Cement-Sand Mixture of the AMERON company, New-York Publishers, 1978, pp. 548-601).
To apply the cement-sand mixture on the inside of a pipeline use is made of a device, comprising a mechanism for applying the mixture on the pipeline surface, a system for feeding the mixture to the said mechanism, a compressor for imparting rotation to the working member of the application mechanism and a pull winch.
The cement-sand mixture application mechanism is connected by a wire rope with the pull winch, and by hoses--with the compressor and the mixture feed system. The mixture feed system and the compressor are fitted with electric motors and drums.
As the wire rope and hoses leave the pipeline, the hoses are disconnected from the rope and manually placed near the pipeline.
Once the coating has been applied, the application mechanism with the hoses and the rope are removed from the pipeline, the mixture feed hoses are disconnected from the rope and washed with water. Thereafter, the rope and the hoses are wound on respective drums.
This sequence of operations prolongs the entire technological cycle of applying the coating on the internal surface of the pipeline and increases the expenditure of manual labour and requires numerous service personnel. Besides, in case of sudden stoppages of the device, the cement-sand mixture is likely to solidify in the hoses.